In the proposed studies, we plan to synthesize chromogenic substrates for certain endoglycosidases. A variety of synthetic sugar derivatives required for the substrate specificity of such enzymes will be made available. The so-called oxazoline method, halide ion catalyzed reaction of sugar halide with an aglycon, will be extensively used in our synthetic studies. The synthesis of gamma-linked galactosaminides will be accomplished by employing 2-azido 3,4,6-tri-O-acetyl-beta-D-galactopyranosyl halide as glycosylating agents. Interestingly, p-nitrophenyl 2-acetamido-2-deoxy-beta-D-galactopyranosyl-gamma-D-galactopyranoside synthesized in our laboratory, has been found to be chromogenic substrate for endogamma-N-acetyl-gamma-D-galactosaminidase of D-pneumoniae, whereas the other sugar synthetic compound, namely, p-nitrophenyl 2-acetamido-2-deoxy-3-O-beta-D-galactopyranosyl-beta-D-galactopyranoside acts as a competitive inhibitor for this enzyme. The latter synthetic derivatives after reduction will be attached to agarose for affinity chromatography of the enzyme. The present research proposal also includes the synthesis of appropriate ligands for such endo enzymes, in order to attempt the purification of enzymes by affinity chromatography. These ligands, when attached to a solid support without a spacer arm, may be found to be quite efficient for the purification of enzymes. The suitable conditions will be developed for the elution of this enzyme. The present research proposal also includes the purification of endo-beta-D-galactosidase of E. Friendii and endo-beta-D-galactosidase of D.pneumoniae. The availability of our synthetic compounds may result into detection of some unknown endoenzymes.